Method of making end closures for insulated pipes



March 13, 1951 A. H. ISENBERG ET AL METHOD OF MAKING END CLOSURES FOR INSULATED PIPES Filed Oct. 7, 1949 INVENTORS ALEXANDER H mnvama RALPH E. HEDGE-9 BY ATTORNEY Patented Mar. 13, 1951 METHOD OF MAKING END CLOSURES FOR INSULATED PIPES Alexander R. Isenberg, Woodside,,and Ralph E.

Hedges, East Palo Alto, Calif.; said Hedges assignor to said Isenberg Application October 7, 1949, Serial No. 120,028

2 Claims.

This invention relates to an end closure for pouring liquid bitumen into a casing for insulated pipe and method of making such closure.

The invention is adapted especially for advantageous use in making insulated pipe of the type disclosed and described in the co-pending application of Alexander I-I. Isenberg, Serial No. 75,027, filed February 7, 1949, wherein there is a conveyor conduit pipe surrounded by a layer of thermal insulating material, the latter preferably wrapped with a coating of cloth or paper, in turn surrounded by a layer of waterproofing bitumen, or the like, which is pourable when installed and solidifies in situ, the bitumen being in turn surrounded by an outer open-ended forming shell or casing into which the fluidified bitumen is poured through suitable openings spaced therealong. Considerable difficulty has heretofore been encountered in preventing the liquefied bitumen from flowing from the open ends of the casing when it is initially poured and while it is solidifying. And to some extent, the same difficulty has been encountered in handling and shipping the fabricated pipe units in unusually hot temperatures. Various types of closure plates and blocks have been employed at the ends of the fabricated conduit units as retaining means for the liquefied bitumen, butdue to the fact that the previously recited conduit elements, though supposed to be concentric, are frequently slightly eccentric, rigid or non-flexible blocks or closures for the ends of the conduit units to retain the liquid bitumen are not satisfactory.

An object of this invention is to provide a flexible and formable closure for the ends of an insulated pipe conduit unit to retain within the conduit assembly the fluidified bitumen when poured, or when in a non-solidified state, and which may be readily removed for repeated use.

Another object is to provide such an enclosure which may, if desired, remain on the ends of such a conduit unit during shipment and protect the protruding ends of insulation, and be readily removable at place of installation of the conduit.

The invention consists of-an end closure for, and a method of closing ends of a casing of an insulated pipe conduit assembly by application of a flexible wrapper strip member saturated with a liquid adhesive which renders the wrapper quite moldably pliable when wet, and which dries to a stiff, though still flexible, consistency, and in applying one portion of the flexible wrapper, while moldably pliable and wet, circumferentially around a substantial length of the end portion exterior of the casing, and providing a portion of the wrapper strip extending beyond the ends of the casing, and in forming such extended portion radially inwardly to cover the open area of the casing end and into circumferential engagement around an extended portion of an insulation body which is within the casing, and puckering or folding the wet flexible member around the extended portion of the insulation and tying it with a releasable tie member.

One advantageous exemplification of the invention is illustrated in the accompanying drawing, in which:

Fig. l is a fragmentary broken longitudinal view of the invention, partly shown in longitudinal central section.

Fig. 2 is a fragmentary perspective view of one end portion of conduit unit showing one end portion of flexible closure member mounted on the conduit and another portion thereof partly removed.

Fig. 3 is an enlarged vertica1 lateral section on line 3-3 of Fig. 1. J

Fig. 4 is an enlarged fragmentary perspective view of a portion of spacer channel member employed in the conduit unit.

Referring to the drawing in which like reference characters indicate corresponding parts in the several views, N] indicates an insulated pipe conduit unit of the general type described in said copending application. These units may be and usually are prefabricated .at a manufacturing plant and shipped to place of installation, or if preferred may be fabricated at place of installation. Briefly described, in construction these units are fabricated with a conveyor pipe II as a core, usually metal for conveying heating or refrigerating fluids, surrounded by a contacting layer of thermal insulation I2 of any and preferably of confronting preformed semi-circular sections, suitable type, in turn surrounded by a cloth or paper wrapper member I3. Spaced from the wrapped insulation l2, I3, is an outer enclosing casing l4 preferably of sheet metal which serves as an outer forming sheath rather than a weight supporting casing member. It is spaced circumferentially of the wrapped insulation by suitable spider members l5 which have openings l6 therethrough longitudinally of the conduit and, therefore, are referred to as spacer channel members, since they space the casing and insulation relatively and also provide a channel there between through which liquefied bitumen or the like moisture impervious fluid may flow when poured into the casing through openings I1 and solidify in situ.

It will be noted that the conveyor pipe ll is casing.

longer than the insulation member so as to have extending opposite ends I la and that the insulation member, though shorter than the conveyor pipe, is longer than the outer casing I 4 so as to have its opposite ends l2a extending beyond the ends of the outer casing, these extensions being to facilitate installation of a joint member, (not shown) for connecting continuously adjoining conduit units at the place of installation, the joint.

members not being a part of this invention.

In the space between the wrapped insulation [2, l3 and Outer casing 14 is poured a liquefied moisture impervious bitumen material l8 which is a fluid when heated and solidifies upon cooling at normal temperatures. The bitumen which is poured in liquid state through the open-- duit are supposed to be concentrically disposed,

as near as practicable, nevertheless in practice they are not exactly concentric for which reason dimculties have been encountered in closing the openings at the end of the outer casing when pouring the liquid bitumen. End closure plates and blocks have been employed to close the end openings during the pouring and solidifying of the liquid bitumen. These, because of their rigidity, are not satisfactory because they must be fit around the extended member insulation, and if the latter is off exact center, leaks are present around the block or plate; if blocks or plates are inserted into the end openings in the manner of a plug or cork, they prevent the asphalt from flowing completely to the end of the Again, where rigid blocks or plates are employed as end closures, various sizes must be maintained for differing diameters or conduit units.

To meet the cliificulties heretofore encountered, there is provided a flexible end closure generally indicated l9, preferably of textile material and absorbentin character, such as loosely woven canvas or unbleached cotton, cut in strips of greater length than the circumference of the outer. casing so that when wrapped therearound the ends of the strip will overlap for a. substantial area as at 263. If desired, the strip'may be of double layers of material, especially if a light weight quality of material is employed.

The strip is is saturated with a liquid adhesive 2! the bond of which is non-permanent.

The adhesive is also a filler of pores between theoverlapping as fat'jZfl. The opposite edge portion 23 of thestrip which: extends longitudinally beyond the end' of the outer casing, is' folded radially inwardly as at '24to contact the extended portion 12a of 'the body of insulation material and then longitudinally bent outwardly as at 25 so that it is circumferentially against the face of the extended portion l2a of the insulation material. A tie member 25 is securely fastened around the portion of the strip in contact with the insulation, as closely as conveniently macfile of this patent:

ticable to the plane of the end of the outer casing. Thus the open end of the space between the insulation and the outer casing is closed by a flexible closure adaptable to various sizes of casings, and snugly fitting the component elements regardless of their relative concentricity.

With the ends of the space between the insulation and outer casing thus closed, the bitumen or asphalt I8 may be poured in liquid state into the openings i1 and flow through openings 16 of the spacer channel l5, being retained at the end of the casing by the wall of the wrapper member.

Preferably th wrapper member is permitted to dry while Wrapped on the outer casing before the bitumen is poured, but this is not absolutely essential to effective operation.

Since the adhesive bond is non-permanent to the outer casing, the wrapper may be removed after the bitumen has solidified, by merely untying or removing the tie member 26. After removal the wrapper member may again be wetted and again used in like manner, even though a superficial strip of the bitumen may cling tothe wrapper, as at 2?, or the wrapper strip, it may remain on th end of the conduit during shipment and thus prevent the extended end of the insulation member from injury, and be removed at place of installation of the conduit unit before a joint member is installed to connect two units, as previously referred to.

Having dscribed the invention, claimed as patentable is:

l. A method of closing an opening at the end of an insulated conduit which has a central conveyor pipe surrounded in contact by an insulation member which in turn is surrounded by an outer casing spaced from and of shorter length than the insulation member, comprising the steps of applying circumferentially of the end portion of the outer casing, one portion of the width of a flexible wrapper strip wetted with an adhesive having a non-permanent bond to the casing, whereby the remainder of the Width of the wetted strip extends beyond said outer casing, overlapping the terminal ends of the wetted strip, bending the extended portion radially inwardly to overlie the end of the outer casing and the space between the outer casing and the insulation member, and again bending the wetted wrapper strip longitudinally outwardly of the insulation member and circumferentially thereof, and binding the longitudinally bent portion while wet around the circumference of the extended portion of the insulation member.

2. A method as defined in claim 1 and which includes the step of wetting the wrapper strip with an amylaceous adhesive.-

ALEXANDER H. ISENBERG. RALPH E. HEDGE-S.

What is REFERENCES CITED The following references are of record in the UNITED STATES PATENTS Number Name Date 572,901 Lehlbach Dec. 8, 1896 675,447 McMahon June 3, 1901 1,411,386 Sodergreen Apr. 4, 1922 1,823,974 Ferguson Sept. 22, 1931 1,871,508 Gardner Aug. 16, 1932 2,129,680 Durant Sept. 13, 1938 2,347,855 Varga May 2, 1944 

